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Hi
I have 3 TL-WDR4300s in my office and a modem to access the internet.
they are all connected via wire to a 8 port TPLink switch. I also have a WD MyCloud NAS connected to the switch.

they have the same SSID, Same password, channels 1,6,11. One of them has DHCP on and others off. Guest networks off. Nothing connected via USB. Latest Firmwares.
On the devices, there's a LED in shape of a star. If it's blinking it means it's working fine.

After about a day, one stops responding and when that happens, I can't access anything in the network. It basically disables the whole network. When this happens the star is either off with all other lights off, or it's on with other lights off.
This happens to all of them but one more than the others.

I've send that to guarantee for checks and they didn't find any problems (typical!)
I heard HardwareNAT causes this and I've disabled " Current Hardware NAT Status" (kept " Current NAT Status" enabled) and it still happens.
I've tried few other settings and none worked.

Please, if you know how to fix this, help me!